What do the following two equations represent? $x-4y = -1$ $4x+y = 2$
Explanation: Putting the first equation in $y = mx + b$ form gives: $x-4y = -1$ $-4y = -x-1$ $y = \dfrac{1}{4}x + \dfrac{1}{4}$ Putting the second equation in $y = mx + b$ form gives: $4x+y = 2$ $y = -4x+2$ The slopes are negative inverses of each other, so the lines are perpendicular.